1. Field of the Invention
This invention relates to a method for synthesizing high-silica zeolite Alpha containing a platinum-group metal within the zeolite pores, as synthesized, and the use of the zeolite prepared in accordance hereto as a catalyst for organic compound, e.g. hydrocarbon compound, conversion.
2. Discussion of Prior Art
Zeolite Alpha and its conventional preparation are taught by U.S. Pat. No. 3,375,205, the disclosure of which is incorporated herein by reference. It has a distinctive X-ray diffraction pattern which identifies it from other known zeolites. Zeolites Alpha and ZK-4 (U.S. Pat. No. 3,314,752, the disclosure of which is incorporated herein by reference) are isostructural with zeolite A (U.S. Pat. No. 2,882,243, the disclosure of which is incorporated herein by reference).
Applicant knows of no prior art for preparing a high-silica zeolite Alpha containing a platinum-group metal within the zeolite pores. In fact, when one attempts to prepare zeolite Alpha by the convention method, but additionally with a source of tetrammine platinum (II) ions in the reaction mixture, the platinum complex will not survive the long heating period required for crystallization of the reaction mixture at the reaction conditions taught by U.S. Pat. No. 3,375,205. Further, it is not possible to ion exchange platinum-group metals into the pores of zeolites of type A structure, e.g. Alpha, because the critical diameter of the cationic platinum-group metal complex is larger than the diameter of the zeolite pores.